Firing mechanism



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FIRING lVIECl-IANISM John L. Lochhead, Springfield, Mass., assignor to the United States yof America as represented by the Secretary of the Army Application June 3, 1954, Serial No. 434,350

2 Claims. j (Cl. 89-139) (Granted under Title 35, S. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

This invention relates to semiautomatic firearms and particularly to improvements in the ring mechanism thereof.

In semiautomatic iirearms wherein the hammer is actuated to cocked position by a recoiling breech member, it is necessary to provide means for latching the hammer in cocked position while the trigger is still pulled back by the operator and the Sear is in the hammer release position. This is because it is unlikely that the operator will always be able to release the trigger fast enough to return the sear to engaging position before the breech member returns the hammer to cocked position.

One of the conventional means for engaging the hammer is through the use of a secondary sear which latches the recoiled hammer when the trigger is pulled and which delivers the hammer to a trigger actuated sear when the trigger is released. By this means, however, the secondary sear is given a sharp blow by the hammer when passing by during recoil. It is obvious that hereby the latching means on the secondary sear is subject to damage and, further, the secondary sear does not always recover from an excessive rearward thrust by the hammer in time for engagement therewith.

It is, therefore, an object of this invention to provide for semiautomatic firearms an improved ring mechanism which is positive in operation and rugged in construction.

It is another object of this invention to provide for semiautomatic firearms a firing mechanism having a single scar which is held out of engagement with the hammer until released for engagement therewith by a hammer actuated latch member.

It is a still further object of this invention to provide a trigger mechanism wherein the hammer and sear are out of engagement during rotation of the hammer from tiring position and the sear is actuated to engageable position by a hammer actuated member when the hammer reaches recoil position.

The specific object of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which:

Fig. 1 is a fragmentary partially cross-sectioned side view of a rearm showing the tiring mechanism with the hammer in tiring position and the sear and trigger bar in retracted positions;

Fig. 2 is a view similar to Fig. 1 but showing the hammer retracted to recoil position by the bolt and engageable with the latching member, the trigger bar in retracted position and the sear in latching position;

Fig. 3 is a view similar to Fig. 1 but showing the bolt moved forward from recoil position with the hammer engaged by the sear, the nigger bar in normal forward Fig. 4 is a perspective exploded view of the tiring mechanism.

Shown in the figures is a channel-like firearm receiver 12 with a bolt 13 mounted for slidable longitudinal movement therein. Mounted for pivotal rotation in receiver 12 is a hammer 14 having a hollow cylindrical hub portion 15 through which there is rotatably received a transverse axial pin 16. Extending centrally from hub 15 isl a body portion 17 having a tiring pin striker portion 18 and a Sear engaging lip portion 19.

Hammer 14 is arranged to be actuated to recoil position by bolt 13 during recoil ight, as best shown by Fig. 2, and is biased to tiring position by a spring 20 having two double-armed coiled portions 21 which are rotatably mounted on hub 15, one on each side of body portion 17. One arm of each of the coil portions 21 are interconnected by a loop portion 22 which presses forwardly against the rear side of body portion 17. The free arm portions 23 extend rearwardly to engageably bias a sear 24 to latch position. Sear 24 is essentially L-shaped with a leg portion 25 and a foot portion 26 and is pivotally mounted on a pin 48 Which traverses such Sear at the junction of such leg and foot portions. Extending forwardly from the top of leg portion 25 is a ledge 27 which is engageable with lip portion 19 of hammer 14 to releasably latch such hammer in the cocked position. Provided on each side of foot portion 26 is a recess 28 which receives the arm portions 23 of spring 20.

Rearwardly adjacent sear 24 is a trigger bar 29 which is mounted for pivotal movement on a pin 30 which traversesthe upper portion thereof. Provided through the central portion of trigger bar 29 is a longitudinal substantially rectangular opening 31 in which there is mounted the rear end of a latchmember 32. Latch member 32 is mounted to trigger bar 29 for pivotal movement by a transverse pin 33 and is arranged to extend forwardly through a rectangular aperture 34 in sear 24 so that a hook portion 35 on such latch member releasably engages the front side of sear 24 above aperture 34. A portion of latch member 32, noted by 36, extends forwardly from the sear 24 so as to be engageable by hammer 14 when in recoil position. A substantially U-shaped leaf spring 37 is arranged to encircle pin 33 with one end bearing against the bottom side of aperture 34 and the other end against the bottom side of latch member 32 so as to resiliently bias the latch member into resilient engagement with sear 24.

Extending upwardly from the bottom side of trigger bar 29 is a slot 38 which receives a lanyard 39. A Well 40 extends rearwardly from the front side of trigger bar 29 to receive a ball 41 on the end of lanyard 39. A bore 42 in the rear side of trigger bar 29 receives the front end of a compressible coil spring 43 which encircles 1anyard 39. The rear end of spring 43 seats against the forward end of a cylindrical member 44 mounted in a trigger bar stop member 45.

A safety 46 is mounted for slidable movement on the bottom side of receiver 12 and is so arranged that a lug 47 thereon is movable under leg portion 25 of sear 24 to prevent movement of the sear out of engagement with hammer 14.

Operation The firing mechanism of this invention is actuated by the operator pulling rearwardly on lanyard 39 after the rearm is charged to engage lip portion 19 of hammer 14 with ledge portion 27 of sear 24. Ball 41 on the end of lanyard 39 transfers the rearward movement of the lanyard to trigger bar 29 which, during the resulting rearward movement, causes latch member 32 by means of hook portion 35- to pull rearwardly onl sear 24 and thereby release hammer 14. The released hammer 14 is rotated under the urging of spring 20 to tiring pin engagingI position whereby the weapon is tired causing bolt 13 to recoil. During recoil of bolt 13, hammer 14 is counterrotatedl thereby past ledge portion 27 of sear 24, which is still held retracted by the operator, into engagement with portion 36 of latch member 32, as best shown ini Fig. 2. Whereby, latchmember 32 is disengaged from sear 24. which is consequently free to be rotated by spring 20into position for ledge 27 thereon to engage lip portion 1.9 of the hammer during the ensuing rotation thereof. As hammer 14 is held in engagement with latch member 32 during the cyclic change of bolt 13, there is ample time-for sear 24 to move forwardly into position to engage hammer 14 when freed for rotation by the counterrecoiling bolt. When the operator releases lanyard 39, trigger bar 29 is biased forwardly by spring 43 so that hook portion 35 on latch member 32 reengages sear 24, as best shown by Fig. 3. Thereby, when lanyard 39 is pulled again scar 24 is actuated to release hammer 14 to re another round as hereinbefore described.

From the foregoing it is clearly apparent that there is provided herein a firing mechanism which is simple and rugged in construction and is positive in operation and wherein the latching portion of the sear is not struck by the recoiling hammer to cause damage thereto.

Although a particular embodiment of the invention has been described in detail herein, it is evident that many variations may be devised within the spirit and scope thereof and the following claims are intended to include such variations.

I claim:

1. In a rearm having trigger means for iring the lirearm, a hammer pivotal between a recoil and a tiring position, a sear movable against said hammer, a ledge portion on said sear engageable with a lip portion on said hammer for releasably holding said hammer in a cocked position between said recoil and firing positions, latch means cooperating with the trigger means for disengaging said sear from said hammer to tire theV firearmY and releasably hold said sear out. of the path of said hammer during movement thereof from the. firing to the recoil position, a tongue portion extending from said latch means into the path of said hammer to be movable thereby to disand a tiring position, a sear mounted for pivotal movement between a forward and a rearward position, a ledge portion on said sear cooperable with a lip portion on said hammer for releasably engaging said hammer in av cocked position during movement of said hammer from said recoil position when said sear is in the forward position, a trigger bar mounted on the opposite side of said sear from said hammer for pivotal movement between a forward and a rearward position, manual means for actuating said trigger bar to the rearward position, a latch member pivotally mounted at one end to said trigger bar and slidably supported at the opposite end by said sear, a hook portion on said latch member releasably engageable with the front side of said sear for transferring rearward movement of said trigger bar to said sear` for disengaging said ledge portion from said lip portion, and for releasably holding said sear out of the path of said hammer when said trigger bar is held in the rearward position, a tongue portion extending forwardly from said latch member into the path of said hammer so as to be engaged by said hammer for moving said latch member to disengage said sear from said trigger bar after said lip portion is moved past said ledge portion to prevent contact therebetween during movement of said hammer to the recoil position, and spring means for normally biasing said sear into position for said ledge portionY to engage said lipy portion during movement of said hammer from the recoil to the cocked position.

References Cited in the le of this patent UNITED STATES PATENTS 1,911,859 Frommer May 30, 1933 2,380,326 Norman July 1'0, 1945 FOREIGN PATENTS 6,672 Great Britain of 1913 554,834 Germany July' 14, 1932 

